GB829597A - Improvements in or relating to variable resistors or potentiometers - Google Patents

Abstract

829,597. Variable resistors; couplings between relatively movable conducting parts. EGEN ELECTRIC Ltd., and BOWMAN, A. July 21, 1958 [July 19, 1957], No. 22870/57. Classes 37 and 38 (1). In a variable resistor or potentiometer a resilient wire contact is in the form of a ring shaped to make wiping engagement with a collector, a small portion of the ring being deformed to protrude through an opening in a rotatable annular insulator so as to make contact with the arcuate resistance element, the remainder of the ring being shielded from the resistance element by the insulator. The Specification describes a potentiometer in which part B of a spring wire contact A protrudes through a hole K in the annular insulator D. The contact A is formed from beryllium-copper or phosphor-bronze and is shaped so that the section B makes contact with a carbon resistive track R carried by an insulating disc O. The wire ring A is bent across the diameter at C so that these points make contact with the nickel-silver collector ring V carried on an insulating disc P. The two discs O, P are supported on a moulded insulating boss L by a hollow rivet M and two washers N. The boss L forms a bearing for the annular insulator D, which is flanged at E so as to provide an edge-operated finger control. Terminal posts S secured near the ends of the arcuate track R also provide end stops. The potentiometer may be mounted by means of a screw through the hollow rivet M with the operating flange E projecting through a slot in the panel.